This invention relates generally to the art of building construction, and, more particularly to a novel concrete building panel and the process of producing same.
Various prefabricated concrete panels exist within the prior art. Generally, the object of such prefabricated panels is to provide components to produce wall sections with the components being significantly larger than ordinary building bricks. Frequently such panels are large and cumbersome and must be produced on the site of the actusl construction, so as to minimize the problems associated with transport.
One technique of on site production is disclosed in U.S. Pat. No. 4,104,356 Deutsch et al, wherein reuseable brackets are utilized for securing wood forms for tilt up panels. Such panels are produced on site, and merely tilted from the horizontal casting position into the vertical use position. The concrete panels so prepared are cast adjacent a foundation so that the step of tilting normally results in the panel being placed directly upon the foundation supporting the desired wall structure.
Another prior art prefabricated panel is disclosed in U.S. Pat. No. 3,609,935 to Thomas. Thomas also describes a form for use in producing tilt up concrete modules. A complex overlap joint structure utilizing a special joint element is disclosed by Thomas.
Another technique of adjoining adjacent panels is disclosed in U.S. Pat. No. 2,462,415 to Nagel wherein spline forming locking plates are utilized to join adjacent panels.
U.S. Pat. No. 4,059,939 to Elliott discloses a prefabricated panel comprising an exterior wall of concrete with the concrete being poured over reinforcing bars which extend from one panel to another. The reinforcing bars of one panel are welded to the reinforcing bars of an adjacent panel and a pilaster is poured over the joined reinforcing bars to complete the wall structure.
U.S. Pat. No. 2,703,003 to Ruppel discloses a prefabricated panel having a mechanical interlock arrangement between adjacent panels.
U.S. Pat. No. 3,555,763 to Bloxom discloses a prefabricated lightweight concrete panel having metallic edge defining members about the entire periphery of the panel. The edge defining members are joined together with reinforcing bars between opposite sides with the central reinforcing bars being sufficiently tensioned to effect a width decrease in the central portion of the panel. In effect, the outer channel iron is bowed in the central portion of the panel. A resulting panel when in the vertical position has a decreased width approximately in the midpoint of its vertical extent. The upper and lower extremities of this panel then have a maximum width near the upper and lower corners. This construction facilitates dimensional control when joining a series of panels since the outside dimensions of each panel are determined by the dimensions at the upper and lower extremities of the panel. Bloxom discloses additional embodiments wherein the gap between adjacent edge defining members is filled with a fiberglass composition.
Bloxom additionally discloses an embodiment wherein angle iron is utilized as a temporary form by tack welding the angle iron to the channel iron edge defining members prior to effecting the width change. After casting, the temporary angle iron structure is removed by breaking the tack weld. The resulting panel has a recessed area which is vertically disposed on a resulting wall between the concrete surface and the exposed channel iron. This recessed area may be covered with a metallic strip which is tack welded to one of the channel iron edge defining members.
While the above discussed prior art produces concrete panels suitable for many applications, many problems have remained unrecognized and unsolved within the prior art.